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Chou R, Huffman LH; American Pain Society; American College of Physicians.Chou R, et al.Ann Intern Med. 2007 Oct 2;147(7):492-504. doi: 10.7326/0003-4819-147-7-200710020-00007.Ann Intern Med. 2007.PMID: 17909210Free article.Review.
Chou R, Huffman LH; American Pain Society; American College of Physicians.Chou R, et al.Ann Intern Med. 2007 Oct 2;147(7):505-14. doi: 10.7326/0003-4819-147-7-200710020-00008.Ann Intern Med. 2007.PMID: 17909211Free article.Review.